Abstract
Motivated by fine tuning of the magnetic and topological properties of MnBi2Te4 via defect engineering, in this work, we report the crystal growth of MnBi2Te4 and related compounds using vapor transport method and crystal characterization by measuring elemental ratio, magnetic and transport properties, and scanning tunneling microscopy. For the growth of MnBi2Te4 single crystals, I2, MnI2, MnCl2, TeCl4, and MoCl5 are all effective transport agents; chemical transportation occurs faster in the presence of iodides than chlorides. We further successfully grow MnSb2Te4, MnBi2−xSbxTe4, and Sb-doped MnBi4Te7 crystals. A small temperature gradient< 20∘C between the hot and cold ends of the growth ampoule is critical for the successful crystal growth of MnBi2Te4 and related compounds. Compared to flux grown crystals, vapor transported crystals tend to be Mn stoichiometric, and Sb-bearing compositions have more Mn/Sb site mixing. The vapor transport growth provides a new materials synthesis approach to fine tune the magnetic and topological properties of these intrinsic magnetic topological insulators where controlling defects is vital.
